An endoscopy is a procedure where the inside of your body is examined using an endoscope.


An endoscope is a long, thin, flexible tube that has a light source and a video camera at one end. Images of the inside of your body are relayed to a television screen.

Endoscopes can be inserted into the body through a natural opening, such as the mouth and down the throat, or through the anus (via the bottom).

Alternatively, an endoscope can be inserted through a small surgical cut made in the skin (known as keyhole surgery).

What happens during an endoscopy?

An endoscopy is normally carried out while a person is conscious. It is not usually painful, but can be uncomfortable, so a local anaesthetic or sedative (medication that has a calming effect) may be given to help you relax.

The endoscope is carefully inserted into your body. Exactly where it enters your body will depend on the part of the body being examined.

An endoscopy can take 60 minutes to carry out, depending on what it’s being used for. It will usually be performed on an outpatient basis, which means you will not have to stay in hospital overnight.

Read more about how an endoscopy is performed.


An endoscopy is usually safe, and the risk of serious complications is low.

Possible complications of an endoscopy include an infection in the part of the body that the endoscope is used to examine, and excessive bleeding.

Read more about the risks of an endoscopy.

Types of endoscope

Some of the most commonly used types of endoscopes include:

  • colonoscopes  used to examine your large intestine (colon)
  • gastroscopes  used to examine your oesophagus and stomach
  • endoscopic retrograde cholangiopancreatography (ERCP)  used to check for gallstones
  • broncoscopes  used to examine your lungs and airways

Other types of endoscope include:

An endoscopy can be used to investigate an area of the body if symptoms suggest there might be a problem. It can also be used to help perform some types of keyhole surgery (laparoscopy), such as removing the appendix or gallbladder.

Read more about when an endoscopy is used.

Uses of an endoscopy

An endoscopy is used to investigate unusual symptoms and to help perform types of surgery.  

Investigating symptoms

An endoscopy might be recommended to investigate the following symptoms:

These types of symptoms are usually investigated with a gastroscopy (to examine the upper section of the digestive system) or a colonoscopy (used to examine the bowel). Watch a video on what happens during a colonoscopy.

Other types of endoscopes used to investigate symptoms include:

An endoscope can also be used to remove a small sample of tissue for further analysis. This is known as a biopsy.

Therapeutic endoscopy

Modified endoscopes that have surgical instruments attached to or passed through them can be used to carry out certain surgical procedures. For example, they may be used to:

  • remove gallstonesbladder stones or kidney stones
  • repair a bleeding stomach ulcer
  • place a stent across areas of narrowing or blockage
  • tie and seal the fallopian tubes (a technique carried out when a woman wishes to be sterilised
  • remove small tumours from the lungs or digestive system
  • remove fibroids – non-cancerous growths that can develop inside the womb 

Laparoscopic surgery

A type of endoscope called a laparoscope is used by surgeons as a visual aid when carrying out keyhole surgery (also known as laparoscopic surgery). During this procedure, small cuts are made, meaning there is less post-operative pain and a faster recovery time compared to traditional open surgery.

Common types of keyhole surgery include:

Laparoscopies are also widely used to help diagnose many different conditions and investigate certain symptoms. Read more about when a laparoscopy is used.

How an endoscopy is performed

Most endoscopies are carried out at a local hospital, although some larger GP surgeries may offer the procedure.

Before having an endoscopy

Depending on what part of your body is being examined, you may be asked to avoid eating and drinking for several hours beforehand.

If you are having a colonoscopy or sigmoidoscopy, you may also be given a laxative to help clear stools from your bowels.

In some cases, you may also need antibiotics to reduce the risk of an infection.

If you are taking a medicine to thin your blood, such as warfarin or clopidogrel, you may be asked to stop taking it for a few days before having your endoscopy. This is to prevent excessive bleeding during the procedure. However, do not stop taking any prescribed medicine unless your GP or specialist advises you to do so.

The endoscopy procedure

An endoscopy is not usually painful, although it may feel uncomfortable.

Endoscopies do not usually require a general anaesthetic (with the exception of an arthroscopy). However, you may be given a local anaesthetic to numb a specific area of your body. This may be in the form of a spray or lozenge to numb your throat, for example.  

You may also be offered a sedative, which makes you feel more relaxed and less aware of what is going on around you.

The endoscope is carefully guided into your body. Exactly where it enters will depend on the part of your body being examined. This may include your:

  • throat
  • anus (the opening through which stools are passed out of the body)
  • urethra (the tube through which urine passes out of the body)

To perform keyhole surgery (laparoscopy), the endoscope is inserted into a small cut your surgeon makes in your skin.

Depending on the exact nature of the procedure and its objectives, an endoscopy can take anywhere between 15 and 60 minutes to carry out. It will usually be performed on an outpatient basis, which means you will not have to stay in hospital overnight.

Wireless capsule endoscopy

A wireless capsule endoscopy is a relatively new kind of endoscopy procedure. It involves swallowing a capsule that is able to wirelessly transmit images of the inside of your stomach and digestive system. The capsule is the size of a large pill and leaves your body naturally when you go to the toilet.

It’s often used to investigate internal bleeding in the digestive system, when there is no obvious cause.

There are some complications associated with wireless capsule endoscopy. Swallowing the capsule can be difficult, as can passing it naturally. The capsule can also get caught in the narrow areas of your bowel, causing a blockage.

After an endoscopy

After having an endoscopy, you will probably need to rest for about an hour until the effects of the local anaesthetic and/or the sedative have worn off. If you choose to take a sedative, you will need to have a friend or relative take you home after the procedure.

If your bladder is being examined (cystoscopy), you may notice some blood in your urine, although this should pass within 24 hours of having the procedure. If you still have blood in your urine after these 24 hours have passed, contact your GP.

Risks of an endoscopy

An endoscopy is usually a safe procedure and the risk of serious complications is very low.

Possible complications include:

  • an infection in a part of the body the endoscope is used to examine  which may require treatment with antibiotics
  • piercing or tearing (perforation) of an organ, or excessive bleeding  which may require surgery to repair damage to the tissues or organ, and sometimes a blood transfusion


Sedation is usually safe, but it can occasionally cause complications, including:

  • feeling or being sick
  • a burning sensation at the site of the injection
  • saliva or, rarely, small particles of food falling into the lungs, triggering an infection (aspiration pneumonia)
  • irregular heartbeat or low blood pressure
  • breathing difficulties

When to seek medical help

Contact your GP if you notice any signs of infection in the area of your body where the endoscope was inserted. Signs of infection include:

  • redness
  • pain
  • swelling
  • a discharge of fluids or pus
  • a high temperature (fever) of 38C (100.4F) or above

A number of other signs could indicate a complication after having an endoscopy. These include:

  • black or very dark coloured stools
  • shortness of breath 
  • severe and persistent abdominal pain
  • vomiting blood
  • chest pain

Contact your GP or visit the accident and emergency (A&E) department of your local hospital immediately if you notice any of these signs and symptoms. 

Anaesthetic is a drug used to either numb a part of the body (local) or to put a patient to sleep (general) during surgery.
Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.